East of EDEN
by Wizarmonfan
Summary: Cyber Sleuth, alternate canon AU. When Arata Sanada tried to help Nokia and Ami escape from the Eater, it ended up claiming him as its victim instead. As if that didn't turn his life upside down enough, then he meets a certain "Yuuko Yamashina". Co-write with Dacciiuu.
1. Chapter 1

"Hey! You're running off by yourself?" lectured the girl. "You can't just think about yourself, you know!"

"Is that so?" replied the boy, smirking and folding his arms contemptuously. "It's gotten me to where I am today."

Getting angrier by the second, the girl wagged her finger at the boy and was about to deliver a comeback when she was interrupted by a sudden flash of light. A portal was materializing out of thin air; a hideous tentacled entity slowly began to emerge from it.

"W… what is that?" she stammered, her face morphing from harried to horrified.

"It can't be..." replied the boy, his mouth agape in awe. "The 'Black Monster of EDEN'!"

At once, the boy turned to the girl and her companion, his face strained with tension.

"Get away from that thing and get ready to log out! I'll break the lock!"

A screen appearing in front of him, the boy began typing away frantically.

"C'mon… c'mon," he muttered as he typed, his forehead breaking out with beads of sweat. "Done! Nokia, Ami… get the hell out of here!"

But the girl stood standing where she was, completely paralyzed by fear, as the entity slowly moved towards her.

"What are you waiting for, Nokia?" shouted the boy. "Move it!"

No response. Grabbing her by the arm, he began to pull her towards the exit.

"Hey! What do you think you're doing?" she asked indignantly as she was dragged along.

"Saving your arse!" he replied, practically throwing her onto the exit; immediately, she ascended into the air. The boy quickly turned towards the remaining girl. "Are you going to do this the easy way, Ami? Or am I gonna have to drag you, kicking and screaming?"

The girl didn't need to be told twice. At full speed, she ran towards to exit and quickly went up towards the heavens. Finally, someone with common sense.

Now that the girls were gone, the boy turned and headed towards the exit himself. Just as he was about to set foot upon it, he felt a tentacle wrap itself around his leg, tripping him up. Everything began to fade into static. Just barely, he was able to make out the sound of his Digivice as it droned away…

"Warning: an unexpected error occurred during the logout process for Arata Sanada…"

…

Arata came to on a busy Shinjuku road, his form half-cyber. A policewoman he would later get to know as Makiko Date found his appearance so gross, she wanted to arrest him on the spot. But he was rescued by a car pulling up in front of him. The passenger door opened to reveal a tall blonde, who drove him back to her business: the Kuremi Detective Agency.

The woman introduced herself as Kyoko Kuremi, while she pondered on his half-cyber body. She suggested for him to retrieve junk data in Kowloon to effect a proper 'casing' and make him look normal again. He did so and returned to the Agency, with his Keramon beside him.

Then, an old detective came in, a friend of Kyoko's deceased father and herself. He introduced himself as Matayoshi and talked about a rumour on EDEN Syndrome, which prompted Kyoko to investigate the hospital after he left.

Down the end of the hallway, Arata saw a quiet girl with black hair talking with a nurse. The nurse stroked the girl's face, reassuring her about something – he wasn't sure what, the nurse had said it quietly before hurrying to do her next duty.

He and the girl stared at each other for a bit. Arata said hello, but the girl walked off in the end. He received orders from Kyoko to check out the special ward and go in through the nurse's station. Arata Connect Jumped through the nurse's station and got to the other end after training his Digimon, including his new Koromon.

He was surprised to see his real body in the isolation ward, realizing he did indeed have EDEN Syndrome. Arata read the EDEN files and walked back out to the hallway, where he once again encountered the shy girl.

"Why are you here?" She gasped, raising her hands to cover her mouth. "This area is supposed to be off-limits, with guards watching over the only entrance. How did you get in here? Did you do something to the guards? Who even are you?" The girl finally dropped her hands and gestured with her right.

Arata smirked and gave a chuckle. "Arata Sanada, detective's assistant."

The girl blushed red and looked curious. "Is Kuremi… I see. Well, never mind, then. You came to investigate EDEN Syndrome, right?" She turned to one side, her hands slightly raised. "Was there something you wanted to ask? I'll answer your questions. Don't get me wrong. I'm just trying to come clean in order to clear my own name here. I am in debt to Kamishiro, so if you have a few questions, I can answer them, I think."

Arata folded his arms. "Is there a cure for EDEN Syndrome?"

"I've never heard of anyone recovering from it. Someone I know has been stuck in a deep sleep... for eight years now." The girl looked down, as if she was not hopeful of his recovery. "I'm sure he'll be fine. Someday he's sure to wake up. For now, all I can do is wait."

Arata nodded, taking in the information. "What happens if someone contracts EDEN Syndrome?"

"What happens?" The girl asked, looking at him still with a flushed face. "Well, as you can see, patients with EDEN Syndrome all fall into a coma. I've heard of no other symptoms. Do you know someone who's shown others?"

Arata shook his head, before glancing to the isolation ward where his own body lay in a coma. "Who is that patient?"

The girl wandered over with him. "This patient here? They were just brought in. They weren't here a few days ago. Oh! You two look exactly alike! Do you have a twin perhaps?"

Arata looked down, his bangs covering his eyes. _It's my own body_. Looking up again, he shook his head. "No."

"Hmm, I see. That's… quite the coincidental resemblance then," the girl admitted.

"There are rumours that Kamishiro's involved in a conspiracy," Arata stated.

The girl leaned down sharply, placing her hands on her knees. "That's a… misunderstanding! A mistake! Kamishiro wants to find a cure for EDEN Syndrome, too! That was they built this special ward and have specialists working around the clock looking for a cure. It's ridiculous that anyone should suffer because of EDEN! I've… I've got to do something!"

Arata glanced at her, a questioning expression on his face. Then Kyoko called in, letting him know an uninvited guest was on the way, terminating the call when she was finished.

They both turned to the entrance and listened to a woman speak in such an absurd tone to the guards. The girl told Arata he needed to hide and quickly. To save further embarrassment, for the girl and himself, he did so. Arata used the computer, where the EDEN files were, to Connect Jump away from being discovered and return to where Kyoko was waiting for him.

…

 **A/N** : Another co-write from Dai and myself, our first Cyber Sleuth fic. Please enjoy and review.

 **Challenges** : Gameverse #19: fuzzy; Pairing Diversity #24: embrace; Too Many Cookies #19: protection; AU Diversity (alternate canon! AU) #32: awesome; Game and Manga Non-Flash #025: drama; General section M #2: alternate timeline; AU Set #1: alternate timeline; and finally, what if challenge.


	2. Chapter 2

The sound of an opening door interrupted the conversation Arata was having with Kyoko.

"Um… is this the Kuremi Detective Agency?"

That voice… it was very familiar…

"It's you!"

In walked the very same girl Arata had met earlier at the hospital.

"What's this?" asked Kyoko. "You two know each other?"

"Define 'know'," replied Arata, grinning cheekily.

"I wouldn't put it that way," said the girl as she looked away shyly.

"Hmm," intoned Kyoko, intrigued by the palpable tension in the room. "Well, regardless, you are Yuuko Yamashina, my new client?"

"Yes… I am Yuuko Yamashina," replied the girl, hesitatingly.

"Let me inquire, then, about the details of the case. Please, have a seat."

"My father has… disappeared," explained Yuuko as she sat down, ill-at-ease, on a sofa.

"Do you have any info on your father?" asked Kyoko.

"Yes… I'll send you the basic data… but the only possible clue I have would be the EDEN account he used. When you query the account info, it says it's still currently active, but…"

"There's no response when you call?" Kyoko interjected.

"None whatsoever..." Yuuko replied, letting out a sigh. "Please… find my father…"

Kyoko folded her arms together and nodded her head sagely in reply.

"I understand. We'll take the case on."

"...'we'?" asked the girl, apprehensively.

"Yes, 'we'!" exclaimed the boy, locking eyes with Yuuko and smiling playfully at her. "Assistant detective Arata, at your service!"

"I see… well… thank you very much..." she replied, suddenly appearing even more flustered than before.

"Let's get started!" announced Kyoko. "I'll let you know if there are any developments. Would you mind giving me your contact information?"

Yuuko shook her head nervously and looked towards the ground.

"No… that won't be necessary… I'll come by again in a little while. I must be going now… goodbye, Miss Kuremi…"

Briefly, the girl raised her head, making eye contact with the boy.

"… Goodbye, Arata-san..." she said, before hurrying outside.

"Very interesting..." observed Kyoko, glancing knowingly at Arata before heading over to her computer and beginning to type. "It seems Mr. Yamashina's account info checks out. I believe someone has hacked this account. There are multiple Makoto Yamashinas wandering through EDEN…"

She paused for a moment, furrowing her brow and typing away.

"I want you to start by tracking down the active traces of the Yamashina account. Take your investigation to EDEN and ask questions."

"Understood!" replied Arata, tipping the hood of his sweatshirt in a salute.

"One more thing," said Kyoko, smiling purposefully at her assistant. "I trust there won't be any… shall we say… 'conflicts of interest' generated by you taking this case on?"

"… What? No, of course not!" said the boy, beginning ever-so-slightly to blush. "She's just a friend!"

"Is she now? I consider Mr. Matayoshi my friend, but I don't blush whenever I talk about him."

Arata sheepishly looked away, his face flushing noticeably now.

"Be professional about this," warned Kyoko. "Don't let your personal feelings get in the way of your investigation. Well, having said that… I think it's about time you returned to EDEN."


	3. Chapter 3

After asking multiple people for information, Arata found himself at the back of Kowloon level 2. He had evolved his Koromon into Agumon, his Tanemon was now a Renamon and his Keramon had become a Kurisarimon.

Approaching a small group of masked people, he was confronted by a teen with light brown hair. "Huh? Who the heck're you?" The masked boy spoke aggressively. "You yankin' my chain? Showin' up here like this? I'm gonna kick you right on outta here!"

Arata showed him the Zaxon mask he'd picked up along the way.

"I've got infinite extra lives!" The boy boasted, before doing a double take and studying the mask properly. "Whoa, wait, what? Are you with them too? A newbie? Did you raid someone's account?" He folded his arms, appearing impressed. "Well, excellent! Next time, let's raid together! You promise? You came at a good time. You with me?"

Arata opened his mouth to speak, but didn't get the chance as the masked hacker showed him a masked man.

"Have a look over there. That's Mephisto-san. Mephisto-san buys any hijacked accounts from us directly."

Seeming to realize this man may provide him with the answers he and Kyoko need, Arata walked closer.

"What, you're off already? Mephisto-san's a little crazy, so be careful!"

Arata only needed to take one look at Mephisto to know he was being possessed, as his movements were jerky and not at all natural. He spoke with the man, wincing when the man wanted him to hand over the account. He shook his head, causing Mephisto to lose it.

"Whoa! What did you do to him? Mephisto-san, are you rolling?" The masked boy pleaded. "Hey, calm down, Mephisto-san! Look, you're freaking the newbie out!"

An anguished scream later and a Growmon materialized, alarming the masked boy. Arata realized now was as good as ever, since the teen knew Mephisto was no longer technically alive.

"Hey, I don't know your name… But did you want to join me after this?"

It was a long stretch and one that the boy might not even accept, but Arata had a feeling he would.

His Demons mask was off and on the ground and terrified green eyes stared back. "S-Sure. Jimiken won't miss me." The boy moved back so as not to impede Arata's fight with the Adult level Digimon.

The fight took a little while, but the forcibly hacked accounts were retrieved. Arata and his new ally returned to the detective agency.


	4. Chapter 4

"Welcome back, my dear Watson," said Kyoko as Arata entered the detective agency. Spotting the green-eyed boy walking behind him, she raised an eyebrow quizzically.

"You're keeping him?" she asked, as if the boy were some sort of wild animal.

"He has a name, you know. It's Kenji."

"Yo!" exclaimed the hacker, nervously peeking out from behind Arata and waving to the detective, who was none too amused.

"If there's any trouble from your friend here, I'm holding you responsible. Understood? Still, in any case, you performed well out there today."

"Hey, it's all in a day's work, as they say…"

"After you obtained Yamashina's account, I did some work of my own," she replied, cracking a cryptic smile. "I looked into his family data, and the results were… intriguing, to say the least."

"… Huh?"

"Your friend 'Yuuko Yamashina' isn't who she claims to be. She's not the daughter of Mr. Yamashina… who, I'd like to add, appears to be very much alive and well."

Arata's mouth opened as if he were about to speak, but his mind just couldn't seem to pass the right words together for a reply.

"I think we should pay a visit to this 'disappeared' man's house. I'd like to hear his side of the story."

"Uhh… yeah, that sounds like a good idea..." he replied absent-mindedly, his thoughts miles away from their conversation. Who was this girl, really? And why had she lied to them? Arata pondered those questions time and time again, as if his consciousness were stuck in a loop, as he, Kyoko and Kenji made their way to the Yamashina residence. It was only when he heard Kyoko knocking at the apartment door that his mind was jolted back to the present.

A bespectacled man slowly opened the door in response. "Yes? Can I help you?"

"Good afternoon," replied Kyoko genially. "This is the Yamashina residence, is it not?"

"Yes… but who are you?"

"I'm actually looking for someone. I don't wish to impose, but may I please ask your name, sir?"

"I'm Makoto Yamashina," he replied, cocking his head in confusion. "But why…"

"Thank you, Mr. Yamashina. One more question; I heard someone in this area has gone missing. Have you any idea who this could be?"

"A missing person? No, this is the first I'm hearing of it."

"I see. May I please speak with your family about this as well?"

"My wife and daughter are away at the moment, but…"

The man was interrupted mid-sentence by a female voice calling out "Daddy, what's the matter?"

Kenji let out a yelp of surprise, caught off guard by the unexpected voice. He, Kyoko, and Arata turned around to face the speaker; in front of them stood an unfamiliar-looking girl.

"Ah, you're home!" exclaimed the man. "Wonderful timing! This is my daughter, Chika."

"Chika?" Arata muttered to himself. "Chika!"

"This is your only daughter?" asked Kyoko. "You have no other children?"

"No. Chika is an only child."

"Who are you, anyway?" inquired the girl.

"They're asking about a missing person," answered her father.

"Missing person? I haven't heard anything about that."

"There you have it," said Mr. Yamashina, shrugging. "Sorry we couldn't be of more help."

"On the contrary!" replied Kyoko. "You provided us with all the information we needed! By the way, Mr. Yamashina, are you aware that your EDEN account was hacked?"

"… EDEN?" repeated the man, recoiling at the very sound of the word.

"However, we restored your account. You can use it freely now."

The man simply stared back at them, wordlessly.

"Is something wrong, Mr. Yamashina?"

"Please, just… leave!" shouted Chika. "We don't know anything about a missing person! Just leave, now!"

The girl ran inside, leaving her father to shut the door on them without saying another word.

"Most fascinating," mused Kyoko, placing her hand upon her chin. "This Chika is certainly Mr. Yamashina's daughter… which means that our mutual acquaintance pretended to be his daughter for the case! I'm not interested in why she tried to deceive us… but she wanted to find something out about Mr. Yamashina. What's the connection?"

The detective stared off into space for a few moments, pondering her own question.

"In any case, our client said she'd return to the agency. Let's have ourselves some coffee and wait for her!"

"Coffee?" said Kenji, his wild green eyes widening in excitement. "Oh man! I love coffee!"

Arata stifled a chuckle. His new friend was going to be in for quite a surprise…


	5. Chapter 5

"Ack!…" Kenji fell to the floor, choking on whatever was in Kyoko's coffee. Arata laughed, before helping Kenji up. "… Urgh. Never touching that again."

Kyoko merely watched the ex-Demon carefully, before turning to the door as Yuuko arrived.

"Hello there," she greeted quietly.

"You came. And much earlier than expected. You are indeed an excellent client," Kyoko started off. "Please, take a seat on the sofa. The investigation has concluded. I can offer you my report."

Yuuko glanced to her right, seeing Arata and a new face. She looked away slightly, as if sensing Arata's displeasure and sat down on the sofa, flushing red in the face.

"… Here are the results of the investigation. A hacker team known as Zaxon was involved in the account raid."

"Zaxon?!" Yuuko was in disbelief.

"Yeah! My former colleag-" Kenji started to interrupt, but was cut off by a scowl from Arata.

"Makoto Yamashina is not missing at all. He's living a normal life. Happily, with his daughter Chika and his wife."

"..." Yuuko hesitated, knowing they'd flushed her out into the open.

"I'd like to bring this investigation to a close, if you don't mind."

"… There's no problem. Thank you very much."

Arata straightened up, knowing his chance would flee soon. "Why?"

When Yuuko looked over to him, his arms were folded and he was frowning. She looked away again, covering the right side of her face with a hand. "… I'm sorry." Yuuko turned towards the door. "I'll be back."

As she left, Kyoko's voice made her stop once more. "You're welcome at any time. Next time, feel free to use your real name. Miss Yuuko Kamishiro..."

Yuuko kept walking.

Arata was beyond seething as he turned away and slammed his fist on Kyoko's office desk. "Why?! I thought… trust… her…"


End file.
